Can anyone offer me any wisdom regarding 30-45L civvy daysacks for hiking? I've seen a lot of Berghaus Freeflows on offer- anyone got/used one? What's the deal with the zippy-bits on the sides of a lot of rucksacks now? Do they increase the main compartment or are they just folding pockets? Oh, and I'm preferably after something that is being given away FREE by some charity for financially incompetent outdoorsmen. Failing that, anything much more than Â£50 and i'll resort to using a bin-bag on a stick.